Method of manufacturing printed circuit board having flow preventing dam

Abstract

A method of manufacturing a printed circuit board having a flow preventing dam, including: applying a dry film resist on a base substrate having a solder pad, and then primarily exposing the dry film resist to light; secondarily exposing the primarily exposed dry film resist formed on a peripheral area of the base substrate to light, thus forming a flow preventing dam; removing the unexposed dry film resist to expose the solder pad, thus forming an opening; printing the opening with a solder paste, and then forming a solder bump through a reflow process; and removing the primarily exposed dry film resist.

1. A method of manufacturing a printed circuit board having a flow preventing dam, comprising:
 applying a dry film resist on a base substrate having a solder pad, and then primarily exposing the dry film resist to light; 
 secondarily exposing the primarily exposed dry film resist formed on a peripheral area of the base substrate to light, the secondarily exposed dry film resist being formed in a state of being overcured, thus forming a flow preventing dam; 
 removing the unexposed dry film resist to expose the solder pad, thus forming an opening; 
 printing the opening with a solder paste, and then forming a solder bump through a reflow process; and 
 removing the primarily exposed dry film resist. 
 
     
     
       2. The method as set forth in  claim 1 , further comprising flip chip bonding a semiconductor chip to the base substrate by use of the solder bump formed on the solder pad of the base substrate, after removing the primarily exposed dry film resist. 
     
     
       3. The method as set forth in  claim 2 , further comprising introducing an underfill solution into a gap between the semiconductor chip and the base substrate, after flip chip bonding the semiconductor chip. 
     
     
       4. The method as set forth in  claim 2 , wherein the flow preventing dam is provided to protrude from the base substrate along an outer edge of the semiconductor chip, in order to prevent outflow of an underfill solution which is introduced into the gap between the semiconductor chip and the base substrate. 
     
     
       5. The method as set forth in  claim 2 , wherein the flow preventing dam is formed to be lower than an upper surface of the semiconductor chip which is flip chip bonded to the base substrate and to be higher than the gap between the semiconductor chip and the base substrate. 
     
     
       6. The method as set forth in  claim 2 , wherein the flow preventing dam is provided between the outer edge of the base substrate and the outer edge of the semiconductor chip. 
     
     
       7. The method as set forth in  claim 1 , wherein a solder resist layer having an opening for exposing the solder pad is formed on the base substrate. 
     
     
       8. A method of manufacturing a printed circuit board having a flow preventing dam, comprising:
 applying a dry film resist on a base substrate having a solder pad, and then primarily exposing the dry film resist to light; 
 secondarily exposing the primarily exposed dry film resist formed on a peripheral area of the base substrate to light, thus forming a flow preventing dam; 
 removing the unexposed dry film resist to expose the solder pad, thus forming an opening; 
 printing the opening with a solder paste, and then forming a solder bump through a reflow process; 
 removing the primarily exposed dry film resist; and 
 flip chip bonding a semiconductor chip to the base substrate by use of the solder bump formed on the solder pad of the base substrate, after removing the primarily exposed dry film resist, 
 the flow preventing dam provided to protrude from the base substrate along an outer edge of the semiconductor chip, in order to prevent outflow of an underfill solution which is introduced into the gap between the semiconductor chip and the base substrate. 
 
     
     
       9. A method of manufacturing a printed circuit board having a flow preventing dam, comprising:
 applying a dry film resist on a base substrate having a solder pad, and then primarily exposing the dry film resist to light; 
 secondarily exposing the primarily exposed dry film resist formed on a peripheral area of the base substrate to light, thus forming a flow preventing dam; 
 removing the unexposed dry film resist to expose the solder pad, thus forming an opening; 
 printing the opening with a solder paste, and then forming a solder bump through a reflow process; 
 removing the primarily exposed dry film resist; and 
 flip chip bonding a semiconductor chip to the base substrate by use of the solder bump formed on the solder pad of the base substrate, after removing the primarily exposed dry film resist, 
 the flow preventing dam formed to be lower than an upper surface of the semiconductor chip which is flip chip bonded to the base substrate and to be higher than the gap between the semiconductor chip and the base substrate. 
 
     
     
       10. A method of manufacturing a printed circuit board having a flow preventing dam, comprising:
 applying a dry film resist on a base substrate having a solder pad, and then primarily exposing the dry film resist to light; 
 secondarily exposing the primarily exposed dry film resist formed on a peripheral area of the base substrate to light, thus forming a flow preventing dam; 
 removing the unexposed dry film resist to expose the solder pad, thus forming an opening; 
 printing the opening with a solder paste, and then forming a solder bump through a reflow process; 
 removing the primarily exposed dry film resist; and 
 flip chip bonding a semiconductor chip to the base substrate by use of the solder bump formed on the solder pad of the base substrate, after removing the primarily exposed dry film resist, 
 the flow preventing dam provided between the outer edge of the base substrate and the outer edge of the semiconductor chip.